Servo valves and solenoids can be used to control fluid flow, for example, in hydraulic systems and continuous fluid flow systems. In some implementations, servo valves include a movable piston in a housing actuated by a movable flapper.
In commercial airline applications the more time an aircraft can remain in service, as opposed to being grounded awaiting repair, the more passenger revenue the plane can generate. In military aircraft applications, the more time an aircraft can remain in service, the greater the capability of that aircraft to perform its mission when needed.